1. Field of the Invention
The present invention relates to a structure of a sealing member that is provided in an imaging lens barrel in an imaging apparatus such as a digital camera.
2. Description of the Related Art
A digital camera in which data for a photographed image is stored in a memory obtains image information by an imaging element. Disposing an optical filter having a function of controlling the wavelength of the incident light in front of an imaging element and in an optical axis direction is a typical configuration. Note that a configuration in which a glass plate is disposed in the manner of an optical filter is also known.
In order to prevent a foreign matter such as contaminants that adhere to the imaging surface of an imaging element from appearing as a ghost image in a photographed image, a sealing member that is formed by elastic material such as rubber is disposed between the optical filter and the imaging element. Normally, a method in which the sealing member is held by restricting the edges is used, but because the sealing member elastically deforms comparatively freely, holding the sealing member is a difficult. In addition, in the case of a method in which the optical filter is fastened to the holding member of an imaging element by an adhesive or the like, the operability becomes unfavorable.
Conventionally, a method in which the position and the tilt of the imaging element on the optical axis are finely adjusted is known. A compression spring is provided between a ground plate of an imaging element and a support plate on which the imaging element is attached, a plurality of adjustment screws are used for moving the support plate in the optically axial direction with respect to the ground plate, and an operator changes the amount of screw-in thereof. In this case, a dedicated compression spring becomes necessary, and the operation is troublesome.
Thus, Laid Open Japanese Patent Application No 2005-020103 discloses a configuration in which the edges of an optical filter interposed between rubber pieces and sealed by a metal plate from the front in the optical axis direction. In addition, in the mechanism disclosed in Laid Open Japanese Patent Application No. 2008-193574, instead of adhering the optical filter, an optical member pressing means is provided integrally with the sealing member, and the optical filter is held by being urged toward the support plate of the imaging element.
However, in the conventional technologies, the following situations can occur. In Laid Open Japanese Patent Application No. 2005-020103, because the edge position of the optical filter is determined only by rubber that elastically deforms, the disposition thereof is unstable, and the position is not set. In addition, this is not a configuration that can adjust the position and tilt of the imaging element. In addition, in the Laid Open Japanese Patent Application 2008-193574, when carrying out the adjustment of the position and tilt of an imaging element, the position of the inner periphery of the optical member pressing means changes and is unstable. Thus, there is a possibility that the optical member pressing means may intrude into the photographing light range.